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A study nanocrystalline TiO 2 based on dye sensitized solar cells with quasi solid state electrolytes
摘要： A quasi solid state electrolytes can be done by adding potassium iodide (KI) and iodine (I2) into quasi solid state electrolytes. Consisting 1,2,4,5–tetrakisbromomethyl benzene (TB), ? –butyrolactone (GBL), propylene carbonate (PC), and ethylene carbonate (EC) gelated with sample 1, 2, 3 and 4. Potassium iodide salt poorly soluble in liquid electrolyte, but can dissolve completely in quasi solid state electrolytes. The dye sensitized solar cell (DSSCs) with the quasi solid state electrolytes were fabricated. The results showed that the energy conversion efficiency of light to electricity were 0.052 %, 0.126 %, 0.121 % and 0.125 %., respectively, under irradiation of 80 mW/cm2. The performance of the dye sensitized solar cell with quasi solid state electrolytes is more stable than that of liquid electrolytes.
关键词： TiO2,dye sensitized solar cell,potassium iodide,iodide salts,quasi solid state electrolytes,energy conversion efficiency
更新于2025-09-12 10:27:22
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Performance optimization of a photovoltaic/thermal collector using microencapsulated phase change slurry
摘要： In a photovoltaic/thermal (PV/T) collector, a portion of absorbed solar energy is transformed into electrical energy, and the remaining part is transformed into thermal energy. Increasing waste heat collection and energy conversion rates are important to improve the performance of the PV/T collector. The utilization of microencapsulated phase change slurry (MPCS) in a PV/T collector to cool photovoltaic modules is an effective way, and electrical and thermal performances of the collector are improved. To investigate influences of operating parameters on performances of PV/T collector, numerical simulation is put into effect to analyze influences of the mass fraction of MPCS on the collector performance. The influences of MPCS mass flow rate and collector channel height on collector performances are also studied. When the flow rate is 0.005 kg/s and the channel height is 0.010 m, the PV/T collector obtains the best net efficiency with a MPCS mass concentration of 20 wt%. But electrical efficiency difference between 15 and 20 wt% is not obvious. With the growth in mass fraction, PV temperature drops more and more slowly because outlet fluid has not fully melt. Take PV/T collector performances into consideration, 15 wt% MPCS is a better choice to cool photovoltaic modules.
关键词： microencapsulated phase change slurry,photovoltaic/thermal collector,electrical and thermal performances,energy conversion efficiency
更新于2025-09-12 10:27:22
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Design and Implementation of an IDA-PBC for a Grid Connected Inverter used in a Photovoltaic System
摘要： The paper presents an interconnection damping assignment - passivity based control (IDA-PBC) strategy applied to a grid-connected inverter interfaced Photovoltaic (PV) system. The PV power plant is integrated to the grid using a pulse-width-modulated converter. This is done to extract maximum energy from the renewable resource and feed it to the grid. The main contribution of this paper is to design a nonlinear control law based on IDA-PBC with a desired energy function along with an integral action. In the design of IDA-PBC, the Hamiltonian function is considered as a Lyapunov function candidate for analysing the stability criteria. In this paper, a step by step design procedure of the IDA-PBC is presented and the performance of the controller is compared with a conventional PI-based controller. A simulation study of the system is carried out in Matlab/Simulink environment. Finally, the simulation results show that the IDA-PBC with an integral action performs better during both transient and steady state conditions as compared with the PI-based controller.
关键词： Interconnection and damping assignment,Grid connected inverter,Photovoltaic energy conversion system,Port control Hamiltonian,Passivity based control
更新于2025-09-12 10:27:22
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Light or Heat: What Is Killing Lead Halide Perovskites Under Solar Cell Operation Conditions?
摘要： We report the first systematic assessment of intrinsic photothermal stability of a large panel of complex lead halides APbX3 incorporating different univalent cations (A=CH3NH3+, [NH2CHNH2]+, Cs+) and halogen anions (X=Br, I) using a series of analytical techniques such as UV-vis and x-ray photoelectron spectroscopy, x-ray diffraction, EDX analysis, atomic force and scanning electron microscopy, ESR spectroscopy and mass spectrometry. We show that heat stress and light soaking induce a severe degradation of perovskite films even in the absence of oxygen and moisture. The stability of complex lead halides increases in the order MAPbBr3<MAPbI3<FAPbI3<FAPbBr3<CsPbI3<CsPbBr3, thus featuring all-inorganic perovskites as the most promising absorbers for stable perovskite solar cells. An important correlation was found between the stability of the complex lead halides and the volatility of univalent cation halides incorporated in their structure. The established relationship provides useful guidelines for designing new complex metal halides with immensely improved stability.
关键词： Plasmonics and Optoelectronics,Photothermal Stability,Solar Cell Operation Conditions,Energy Conversion and Storage,Lead Halide Perovskites
更新于2025-09-12 10:27:22
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Performance Evaluation of Single-Junction Indoor Photovoltaic Devices for Different Absorber Bandgaps Under Spectrally Varying White Light-Emitting Diodes
摘要： In this article, we present a detailed theoretical study to predict performance characteristics of single-junction indoor photovoltaic (PV) devices operated under white light emitting diodes (LEDs) having different spectral characteristics. Efficiency limits of both ideal and practical PV converters have been evaluated considering illumination by commercially available white LEDs. The obtained results have been generalized for white LED sources having a wide range of correlated color temperatures (CCTs) and fraction of blue in their corresponding spectrum. Depending on bandgap of the absorber material, both positive and negative correlations are observed between photon conversion efficiency of PV devices and CCT values of the white LED sources. For material bandgaps of ～1.5 eV or lower, higher photon conversion efficiencies are obtained for warm glow white LEDs. On the contrary, white LEDs characterized to emit cool light are found to be more conducive for PV devices having absorber layer bandgaps of ～2 eV or higher. The observed characteristics have been explained in terms of linewidth of the main emission peak and relative intensity of blue emission peak of the irradiating white LED spectrum. Based on the analysis of photon yield, three distinct bandgap ranges of the PV absorber material have also been identified, each of which represents different dependence of PV device performances on the white LED spectral characteristics. These results in effect provide the necessary guidelines for designing homojunction, heterojunction, or tandem PV devices suitable for operation under different practical white LED sources.
关键词： red-green-blue (RGB) white light emitting diodes (LEDs),energy conversion efficiency,photon yield,Correlated color temperature,indoor photovoltaic (PV)
更新于2025-09-12 10:27:22
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Core/Shell Nanocrystal Tailored Carrier Dynamics in Hysteresis-Less Perovskite Solar Cell with ~20% Efficiency and Long Operational Stability
摘要： The ambient stability, hysteresis and trap states in organo-halide perovskite solar cells (PSCs) are correlated to the influence of interlayer interfaces and grain boundaries. Astute incorporation of Cu2ZnSnS4 (CZTS) and Au/CZTS core/shell nanocrystals (NCs) can achieve the goal of simultaneously achieving better performance and ambient stability of the PSCs. With optimized Au/CZTS NC size and concentration in the photoactive layer, power conversion efficiency can be increased up to 19.97±0.6% with ambient air stability ?800 h, as compared to 14.46±1.02% for the unmodified devices. Through efficient carrier generation by CZTS and perovskite, accompanied by the plasmonic effect of Au, carrier density is sufficiently increased as validated from transient absorption spectroscopy. NCs facilitate the interfacial charge transfer by suitable band alignment, and removal of recombination centers such as metallic Pb0, surface defects or impurity sites. NC-embedding also increases the perovskite grain size and assist in pin-hole filling, reducing the trap state density.
关键词： Carrier Dynamics,Perovskite Solar Cells,Plasmonics,Optoelectronics,Energy Conversion and Storage,Operational Stability,Hysteresis-Less,Core/Shell Nanocrystals
更新于2025-09-12 10:27:22
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The Perfect Solar Cell
摘要： Within a few years only, methylammonium lead iodide (MAPbI3), and later more advanced organic metal halide perovskites, have performed an unprecedented rally towards highest power conversion efficiencies. A team of six scientists at Karlsruhe Institute of technology (KIt) has found evidence for ferroelectric domains in MAPbI3 thin-films. For their research, the team was awarded the Erwin-Schr?dinger-Prize of the helmholtz Association and the helmholtz Foundation.
关键词： Perovskite solar cells,Ferroelectric domains,MAPbI3,Photovoltaics,Energy conversion
更新于2025-09-12 10:27:22
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Thin film Sn2S3 via chemical deposition and controlled heating - its prospects as a solar cell absorber
摘要： As a semiconductor of “earth-abundant” elements, Sn2S3 with a bandgap (Eg) close to 1 eV merits attention, but a method to prepare phase-pure thin film remains elusive. We report the formation of Sn2S3 thin film of 360 nm in thickness by heating chemically deposited tin sulfide thin films at 450 oC during 30 – 45 min in presence of sulfur at a pressure, 75 Torr of nitrogen. Energy dispersive x-ray emission spectra and grazing incidence x-ray diffraction established a reaction route for this conversion of SnS completely to Sn2S3 via an intermediate phase, SnS2. The optical bandgap of the material is 1.25 eV (indirect) and 1.75 eV (direct, forbidden). The optical absorption suggests a light-generated current density of 30 mA/cm2 for the Sn2S3 film (360 nm) as a solar cell absorber. Thin film Sn2S3 formed in 30 min heating has a p-type electrical conductivity in the dark of 1x10–4 Ω–1 cm–1, which increases to 3x10–4 Ω–1 cm–1 in 0.2 s under 800 W/m2 tungsten-halogen illumination. An estimate made for its mobility-lifetime product is, 6x10–6 cm2 V–1. We discuss the prospects of this material for solar cells.
关键词： SnS-CUB,Sn2S3,semiconductor thin film,chemical deposition,energy conversion,ottemannite,cubic tin sulfide,renewable energy,optical and electrical properties,solar cells
更新于2025-09-11 14:15:04
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Analysis and optimization of passive cooling approach for free-standing photovoltaic panel: Introduction of slits
摘要： One of the major issues related to market available silicon based photovoltaic (PV) technologies is the performance drop caused by relatively high PV panel operating temperatures. The proper cooling of PV panels can reduce performance degradation and increase the lifetime of convectional PV panels. This paper investigates architecture modifications to market available silicon PV panels with the introduction of slits on the PV panel surface, which enables the passive cooling of PV panels. Two different arrangements of slits were numerically investigated and followed with the optimization approach. A developed numerical model was derived from the referent numerical model that was experimentally validated. For each considered scenario, a detailed flow and thermal analysis was performed which included optimization regarding minimum average PV cell temperatures. The considered slit types differ with slit orientation, i.e. parallel to PV panel tilt-axis (type-A) and perpendicular to PV panel tilt-axis (type-B). In both cases, a detailed analysis and optimization required ~100 CFD simulations to investigate the effects of different slit sizes and all wind directions. Overall, using the considered slit modifications, the average PV cell temperature could be decreased up to 3 °C, where effective cooling with the proposed modification is only reasonable for wind speeds up to 5 m/s.
关键词： Energy conversion efficiency,Renewable energy,Photovoltaics,Numerical analysis,Passive cooling
更新于2025-09-11 14:15:04
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Hybrid Plasmonic-Aerogel Materials as Optical Superheaters with Engineered Resonances
摘要： Solar radiation is a versatile source of energy, convertible to different useful forms of power. A direct path to exploit it is the generation of heat, for applications including passive building heating, but it can also drive secondary energy conversion steps. We present a novel concept for a hybrid material which is both strongly photo-absorbing and with superior characteristics for the insulation of heat. The combination of that two properties is rather unique, and make of this material an optical superheater. To realize such material, we are combining plasmonic nanoheaters with alumina aerogel. In our hybrid material, the aerogel has the double function of providing structural support for plasmonic nanocrystal, which serve as nanoheaters, and reducing the diffusion rate of the heat generated by them, resulting in large local temperature increases under a relatively low radiation intensity. Alongside their optical and photothermal properties, this work includes theoretical discussion on the physical mechanisms impacting the system’s balanced thermal equilibrium.
关键词： surface plasmon resonance,hybrid aerogel,energy conversion,gels,photoheater
更新于2025-09-11 14:15:04